def divide(a,b):
    r = 0
    try:
        print('divide start')
        r = a/b
        print('divide end')
    except ZeroDivisionError as a:
        print(a)
    except TypeError as a:
        print(a)
    except Exception as e:
        print(e)
    return r

def main():
    print('start')
    r = divide('a',0)
    print(r)

if __name__ == '__main__':
    main()